Immunomodulatory Action of Levofloxacin on Cytokine Production in Adults with Community-Acquired Pneumonia

Background: There is growing evidence that certain antibiotics exert their beneficial effects not only by killing or inhibiting the growth of bacterial pathogens but also indirectly by their immunomodulatory up regulatory effect on the immune system. Immunomodulatory effects of antibiotics could possibly influence the degree of the systemic and local response to infection. So, knowledge of their intrinsic influence on the host’s inflammatory response appears to be essential. Fluoroquinolones have been known to exert modulatory activity on immune responses to microbial infection. However the mechanism of this immunmodulation has not been well elucidated. Aim of the Work: To explore the Immunomodulatory effect of the frequently used antimicrobial agent, levofloxacin, through evaluating its effect on the serum level of specific cytokine mediators (TNFα , IL-10) in the pneumonic patients. Patients and Methods: Serum levels of tumor necrosis factor alpha (TNFα ) and Interleukin10 (IL10) have been measured by enzyme linked Immunosorbent assay (ELISA) technique in the sera of 40 patients with community-acquired pneumonia (CAP) before and 10 days after receiving levofloxacin (LVFX), using human TNFα and IL-10 ELISA kit. Results: There was a statistically significant decrease in the mean level of TNFα and a statistically significant increase in the mean level of IL10 in pneumonic patients after a ten days course of levofloxacin therapy. Conclusion: This study revealed that treatment with levofloxacin showed significant inhibitory effect of TNFα as a pro-inflammatory cytokine and a significant stimulatory effect of IL-10 as an anti-inflammatory cytokines which may provide additional benefits in treatment of respiratory tract infections and more efficient eradication of the offending pathogen especially with the emergence of multi-drug resistant microbes. These finding suggested that levofloxacin by its immunomodulatory action on cytokine production may provide additional benefits in patients with chronic pulmonary infections that are independent of its antibacterial properties. Correspondence to: Dr. Sherif I. Kamel, The Department of Tropical Medicine, Faculty of Medicine, Assiut University, Egypt